Syntactic foam is a kind of composite material synthesized by filling a metal, polymer, or ceramic matrix with hollow particles called micro-balloons or hollow micro-spheres. For oil well applications, pure syntactic foams comprise hollow glass microspheres (HGMS) suspended in a thermoset resin matrix. HGMS collapse pressures are not temperature sensitive. However, the mechanical performance of the matrix resin system is temperature dependent. So too is the collapse pressure of the syntactic foam. In FIG. 1, a graph shows typical pressure-strain curves of syntactic foam at different temperatures. In FIG. 5, it can be seen that the hydrostatic collapse pressure HCP decreases with increasing temperature.
The use of syntactic foam is one common option to relieve annular pressure buildup (APB) in subsea wells. Syntactic foams are usually wrapped around the outer casing wall. When the annular pressure exceeds a specific foam crush-pressure at a certain temperature, the foam collapses and gives extra space for the annular fluid to expand and consequently mitigate APB. Simulation of a syntactic foam's behavior during annular fluid expansion (AFE) analysis and casing load analysis can provide valuable information to assist wellbore tubular design.